1. Field of the Invention
This invention relates to a method of preparing breast pads, cups, fronts and the like for use in brassieres and other garments.
It is a primary requisite of breast pads, cups, fronts and the like (hereinafter generically referred to as "breast pads") that they possess and be capable of retaining a smooth, evenly-tapering outline which will confer on the finished brassiere a natural appearance. Further, in addition to the obvious requirements that the breast pads must confer upon the brassiere the necessary support for the female breasts and make the breasts appear larger, the pads, when incorporated into the brassiere, must stand up well under wear, be substantially resilient so as to adapt themselves to the various positions and motions of the wearer, returning always to their original shapes and their shapes and resiliency should not be affected by laundering of the brassiere. Further, the breast pads, when incorporated into the brassiere, should be comfortable; in particular, it has been found to be desirable to provide breast pads which are relatively soft at their centers or nipple areas, but are correspondingly firmer at their sides so as to prevent the pad from collapsing and to give a natural feel to the wearer. Finally, the breast pads should be easy and economical to manufacture; in particular, the method for preparing the breast pads should permit rapid manufacture of the pads with a minimal "scrap" loss of the stock material from which the pads are to be formed.
2. Description of the Prior Art
Methods for molding breast pads from foam materials such as polyurethanes are known in the prior art, as is evidenced by U.S. Pat. No. 3,164,655, issued Jan. 5, 1965 to Jack E. Howard et al. However, this invention differs in several respects from the Howard et al patent and more importantly results in a more rapid, economical process and more comfortable breast pads.
In the Howard patent, a block of the foam material must first be cut so as to provide a thin, hollow blank having a generally conical configuration corresponding to that of the ultimately desired shape of the breast pad. This cutting operation requires expensive, complex equipment, is time-consuming, and is uneconomical, since a substantial amount of "scrap" foam material is left over. In contradistinction thereto, the instant invention starts with a thin (e.g. about 1/2 inch in thickness) generally planar (i.e. "flat") material which can be quickly cut from conventionally-sized foam slabs into blanks of any desired shape depending on the cutting die. Up to 20 blanks of 1/2 inch material can be cut at one stroke in a few seconds using relatively inexpensive, die cutting equipment. Likewise, approximately 40 blanks of 1/4 inch material can be cut using similar die cutting equipment. The Howard method, on the other hand, requires one blank to be sliced at a time, which is much slower and more costly. Further, the starting shape of the Howard blank necessarily requires that the block from which the blank is cut be of cured polyurethane foam material, whereas in the instant invention, either cured or uncured material may be utilized as the stock material.
Howard requires a molding operation of approximately 120 psi pressure, heat of approximately 320.degree. F. and a molding time of approximately two minutes and forty seconds. In the instant invention, it is possible to employ a molding cycle involving only about 60 psi pressure, a heat of approximately 400.degree. F. (which may be varied depending on the temperature of the surroundings and the thickness of the material) and a molding time of only 10 to 40 seconds depending on the type of material, i.e., a molding time of only one-fourth of that of Howard. Further, the instant invention makes use of vacuum to insure that the blank is deformed into and fully seated within the female mold part before molding pressures and temperatures are applied, whereas Howard depends on a molding pressure of double that required in the instant invention. Excessive molding pressures are undesirable in that they may lead to numerous "rejects."